Exhaust fan switch



Nov. 27, 1956 M. M. CAROTHERS 2,772,331

EXHAUST FAN SWITCH Filed Dec. 12, 1955 INVENTOR. MELVIN M. CA ROTH E R5BY i MM M M United States Patent EXHAUST FAN SWITCH Melvin M. Carothers,Eugene, Greg.

Application December 12, 1955, Serial No. 552,328

7 Claims. (Cl. 20084) This invention relates to an exhaust fan switchand more particularly to a Water actuated switch suitable for mountingin the flush tank of a toilet so as to start an exhaust fan when thetoilet bowl is flushed and stop the fan after a time delay which willusually be several minutes.

Various types of time delay switches have been provided for stopping andstarting an exhaust fan for a bathroom or other enclosure containing atoilet. In most cases such switches depend upon manual actuation of theswitch to start the fan and then automatically stop the fan after a timedelay. Various types of time delay devices including dashpots and alsothermostatically operated switches with a heater have been employed butsuch devices have either been expensive or subject to rapiddeterioration or are not capable of operating to provide repeated cyclesof time delay immediately following each other. Also, such switches donot, in general, provide for automatic starting of a fan.

In accordance with the present invention, a switch is provided which isadapted to be mounted within the interior of the flush tank of a toiletso that the exhaust fan is automatically started whenever the toiletbowl is flushed. The switch is simple in construction and utilizes thechanges in the level of the water in the flush tank to produce a timedelay. The time delay is of greater duration than the period it takes toempty and again fill the flush tank, is adjustable over a wide range andthe delay time starts again each time the toilet bowl is flushed.

It is therefore an object of the present invention to provide animproved exhaust fan switch.

Another object of the invention is to provide a time delay switch for anexhaust fan automatically actuated by changing water levels in the flushtank of a toilet when the water level in such flush tank varies.

A further object of the invention is to provide a switch which can beeasily mounted in the flush tank of a toilet to automatically start andthen after a time delay stop an exhaust fan.

A still further object of the invention is to provide a switch actuatedby changing water levels in the flush tank of a toilet so that anexhaust fan connected to such switch is started when the toilet bowl isflushed and is stopped after a time delay of greater length than thetime it takes to again fill the tank.

Other objects and advantages of the invention will appear in thefollowing description of a preferred embodiment of the invention givenin connection with the attached drawing of which:

Fig. 1 is a vertical sectional view through the switch of the presentinvention;

Fig. 2 is a top view of the device of Fig, 1;

Fig. 3 is a horizontal section taken on the line 33 of Fig. 1;

Fig. 4 is a bottom view of the device of Fig. 1;

Fig. 5 is a fragmentary view showing a portion of the outside of thecasing of the device of Fig. 1;

2,772,331 Patented Nov. 27, 1956 Fig. 6 is a fragmentary verticalsection showing a modified water discharge valve; and

Fig. 7 is a schematic diagram showing a suitable cir cuit for the switchof the present invention when employed for stopping and starting a fan.

Referring more particularly to the drawing, the switch of the presentinvention includes a vertically extending casing it) which may be of anydesired cross-sectional shape but preferably is tubular and of thecircular cross section shown. The casing 10 is provided with laterallyextending spring clips 12 of non-corroding spring metal, such as brass,suitably secured thereto and spaced vertically therealong. The clips 12are adapted to fasten the casing 10 to the usual water supply post 14found in flush tanks of toilets and shown in dotted lines in Fig. 1 bymerely pressing the casing 10 sidewise toward such post in a mannercausing the post to enter the clips between the points 16 so that suchclips partially surround the post. The points 16 engage the surface ofthe post to provide secure attachment of the casing to the post. Thecasing is positioned on the post so that a major portion of its heightis submerged in the water when the tank is full, i. e., most of thecasing extends below the upper water level indicated at in The casing 10may be of any suitable non-corroding material, such as a molded orextruded thermoplastic or thermoset resin, and has a collar 20 suitablysecured to its lower end, for example, by screw threads 22. The collarhas a shoulder holding a valve seat member 24 in watertight relationshipagainst the lower end of the casing 10 and the valve seat member isprovided with a centrally disposed opening 26 therein. The valve seatmember 24 cooperates with a float valve 28, preferably in the form of ahollow ball made of any suitable resilient material such as a rubber orrubber-like material. The valve seat member 24 may be of rigid material,for example, it may be made of one of the resins referred to above oralternatively it may be made of a flexible material such as rubber inwhich case the ball 24 may be of rigid material, for example, the ballmay be a table tennis ball. The ball 24 is retained in position adjacentthe valve seat member 24 by a cage, which may for example, be made ofcrossed wires 30 engaging in recesses 32 in the lower portion of thecollar 29. It will be apparent that the ball float valve 23 willdischarge Water from the interior of the casing 10 when the water levelin the tank falls below the valve and that such valve will prevententrance of water into the interior of the casing 16 when the waterlevel again rises above the valve.

The upper end of the casing is closed by a cap 34 secured thereto in anysuitable manner such as by threads 36. The cap 34 is of insulatingmaterial such as one of the resins referred to above and has a pair ofspring contact members 38 secured to its inner surface. The contactmembers are preferably of a non-corroding spring metal, such as brass,and extending laterally of the casing so as to be spaced from each otherand from the top of the cap 34. The contact members each have anupwardly extending portion at one end terminating in a reversely bentportion which may be positioned in one of a pair of spaced recesses inthe lower surface of the cap 34. The portions 40 are held in therecesses by screws 42 which also form spaced electrical connectors forwires .4 positioned exteriorly of the cap 34.

A float 46 which may be of watenproofed cork or other suitable materialis positioned in the interior of the casing 10 adjacent its upperportion. The float has attached thereto by means of a rod 48 an uppercontact element 543 also of non corroding metal. The contact elementextends over the contact members 38 so as to engage such contact memberswhen the float is in its lower position and is raised such above contactmembers when the float is in its upper position shown in Fig. 1. It willbe apparent that the float as will fall to its lower position when theinterior of the chamber llli is emptied of water so as to cause thecontact element 50 to bridge the contact members 38 and close anelectric circuit including the wires 44. When the water in the tankagain rises, the float valve 28 closes the opening 26 in the valve seatmember 2a to prevent water from entering the lower portion of the casing10.

The casing It) is provided with an opening 52 for controlled admissionof water into the casing. As soon as the water in the tank reaches alevel above the opening 52, a small stream of water enters the casing 1%to slowly fill the same and it will be apparent that after a time delay,the float 46 will be carried upwardly to move the bridging contactelement Stl out of contact with the contact members 318. An air vent 53may be provided in the cap 34 to enable air trapped in the casing to beexhausted therefrom and also to enable water to be more rapidlydischarged from the casing lltl when the water level in the flush tankfalls below the valve 28.

A modified form of discharge valve for the lower end of the casing id isshown in Fig. 6 and includes a cap 54 having a discharge opening thereinsurrounded by a tubular gasket 55 of rubber or similar resilient gasketmaterial having its upper end adhesively secured to the outer surface ofthe cap 54 and its lower end providing a valve seat. A valve in the formof a disc 55 of non corrosive metal, such as brass, is pressed againstthe lower end of the gasket 55a by a leaf spring 56 having one endsecured to the disc 55 and its other end reversely bent and engaged in aslot 57 in the lower surface of the cap 54. The spring is secured to thecap by an adjusting screw 58 extending through holes in the reverselybent portions of the spring and screw threaded into the cap 54. Theforce of the spring tending to hold the disc 55 against the gasket 55acan be adjusted by the screw 58 and such force is made just suflicientto engage the disc with the gasket when the water has been dischargedfrom the casing Zltl and the water level in the flush tank is below thedisc. By employing a spring having a low spring force and the adjustmentjust described, the valve opens to discharge water from the casing 10when the water level in the flush tank falls and closes to prevententrance of water into such casing when the water level in the flushtank again raises.

The opening 52 is preferably positioned near the upper end of the casingill but spaced from such upper end so that the contacts 38 and 50 aremaintained aibove the water level in all adjusted positions of thecasing vertically along the water supply post 14 and so that the timerequired to till the major portion of the chamber in the casing lid isadded to the time required for the water in the flush tank to reach thelevel of the opening 52. As is well known, the flush tank of a toiletrapidly fills until the float valve of the flush tank begins to close,after which the increase in water level becornes progressively slower.By vertically adjusting the casing it) along the water supply post 14the time delay before the contacts 50 and are disengaged, after havingbeen engaged by downward movement of the float 46, can be adjustedthrough a considerable range. Calibrations 58a are preferably placed onthe exterior surface of the casing it? adjacent the opening '2, asindicated in Fig. 5. Such calibrations indicate the approximate timedelay in minutes and the casing it) is adjusted so that the appropriatecalibration registers with the final level of water in the flush tankwhen the flush tank float valve has com pletely closed.

Fig. 7 shows an example of a circuit in which the switch including thecontact members 38 and contact element St may be employed. Such circuitmay be supplied from the usual 110 volt house service lines 59 through astepdown transformer no, for example, a

transformer of the door bell ringing type, to secure a low voltage lowpower circuit at the switch. A 6 volt circuit is entirely satisfactoryalthough voltage up to approximately 20 volts can be safely employed.The contacts 38 and are connected in series with the secondary windingof the transformer 60 and the actuating winding of a relay 62 having itsnormally open contacts in series with a fan motor 64 and with the line59.

The operation of the switch of the present invention is believed to beapparent from the above description. The switch casing lid is secured tothe water supply post 14 in the tank by means of the clips 12 so as toextend -be low the upper water level 18. When the water level is at 18,the casing 10 will fill with water and the float 46 will occupy itsupper position such that the low voltage electric circuit including thewires 44 is broken by the contact element Ell. When the toilet bowl isflushed, the water level in the flush tank is lowered below thedischarge valve of Fig. 6, and such valve opens to discharge the waterfrom the casing 10. This causes contact element 5t) to engage contactmembers 38 to cause a closing actuation of relay 62 so as to start thefan motor 64. The water level in the tank thereafter rises to cause thedischarge valve in the lower end of the casing it) to close and as thewater approaches its maximum level, a small stream of water enters thecasing 10 through the opening 52. At a predetermined time after thetoilet bowl has been flushed, the chamber 10 will fill sufficient tocause the float 46 to be carried upwardly and again break the lowvoltage electric circuit to cause the relay 62 to open and stop the fanmotor. The time delay can be adjusted by the user of the switch over aconsiderable time range by varying the vertical height of the casing 10in the flush tank. Thus the time delay may be varied from one or twominutes up to ten or fifteen minutes, the usual time being about fiveminutes. It will be noted that the time cycle starts again each time thetoilet bowl is flushed such that the fan continues to run for apredetermined period of time after the last flushing operation.

I claim:

1. A time delay switch for mounting in a tank in which the level ofwater is varied between two spaced levels, said switch comprising avertically extending casing, means for supporting said casing in saidtank with the lower portion of said casing below the upper and above thelower water level in said tank, a valve for discharging water from saidlower portion when the water level in said tank falls below said valveand for preventing entrance of water into said casing when said waterlevel rises above said valve, said casing having an opening through awall thereof below said upper level of water in said tank for controlledentrance of water into said casing, a float in said casing having anupper and lower position, and an electrical contact actuated by saidfloat to complete an electric circuit when said float is in one of saidpositions and to break said circuit when said float is in the other ofsaid positions.

2. An exhaust fan switch for mounting in the flush tank of a toilet,said switch comprising a vertically extending casing, means forsupporting said casing in said tank with at least a substantial portionthereof below the upper water level in said tank, said casing having adischarge opening for discharging water from the lower portion of saidcasing, a spring actuated valve for said discharge opening, said valvebeing biased to closed position by said spring and opening when thewater level in said tank falls below said valve and closing to prevententrance of water into said casing when said water level rises abovesaid valve, said casing having an opening through a wall thereof below.said upper level of water in said tank for controlled entrance of waterinto said casing, a float in said casing having an upper and lowerposition, and an electrical contact actuated by said float to completean electric circuit when said float is in one of said positions and tobreak said circuit when said float is in the other of said positions.

3. An exhaust fan switch for mounting in the flush tank of a toilet,said switch comprising a vertically extending casing, means includingspring clips for attaching said casing to the water supply post of saidtank with at least a substantial portion of said casing below the upperwater level in said tank, a valve for discharging water from the lowerportion of said casing when the water level in said tank falls belowsaid valve and for closing said lower portion to prevent entrance ofwater into said casing when said Water level rises above said valve,said casing having an opening through a wall thereof adjacent its upperend and below said upper level of water in said tank for controlledentrance of water into said casing, 21 float in said casing having anupper and lower position, and an electrical contact actuated by saidfloat to complete an electric circuit when said float is in one of saidpositions and to break said circuit when said float is in the other ofsaid positions.

4. An exhaust fan switch for mounting in the flush tank of a toilet forstarting a fan when the toilet bowl is flushed and stopping said fanafter a time delay, said switch comprising a vertically extendingcasing, means for supporting said casing in said tank for verticaladjustment and with a substantial portion of the length of said casingbelow the upper water level in said tank, a valve for discharging waterfrom the lower portion of said casing when the water level in said tankfalls below said valve and for closing said lower portion againstentrance of water past said valve when the water level in said tankrises above said valve, said casing having an opening for controlledentrance of water from said tank into said casing when the water levelin said tank rises toward said upper level, a float in said casing andan electrical contact actuated by said float to start said fan when thewater level in said casing falls due to flushing of said toilet bowl andfor stopping said fan after a time delay when the water level in saidchamber rises to raise said float.

5. An exhaust fan switch for mounting in the flush tank of a toilet forstarting a fan when the toilet bowl is flushed and stopping said fanafter a time delay, said switch comprising a vertically extendingcasing, means for attaching said casing to the water supply post of saidtank with a substantial portion of the length of said casing below theupper water level in said tank, a float valve for discharging water fromthe lower portion of said casing when the water level in said tank fallsbelow said valve and for closing said lower portion against entrance ofwater past said valve when the water level in said tank rises above saidvalve, said casing having an opening for controlled entrance of waterfrom said tank into said casing when the water level in said tank risestoward said upper level, a float in said casing and an electricalcontact actuated by said float to start said fan when the water level insaid casing falls due to flushing of said toilet bowl and for stoppingsaid fan after a time delay when the water level in said chamber risesto raise said float.

6 An exhaust fan switch for mounting in the flush tank of a toilet forstarting a fan when the toilet bowl is flushed and stopping said fanafter a time delay, said switch comprising a vertically extendingcasing, means for supporting said casing in said tank for verticaladjustrnent and with a substantial portion of the length of said casingbelow the upper water level in said tank, a discharge opening in thelower end of said casing, a float valve for discharging water throughsaid discharge opening when the water level in said tank falls belowsaid valve and for closing said opening against entrance of water whenthe water level in said tank rises above said valve, said casing havingan opening for controlled entrance of water from said tank into saidcasing when the water level in said tank rises toward said upper level,a float in said casing and an electrical contact actuated by said floatto start said fan when the water level in said casing falls due toflushing of said toilet bowl and for stopping said fan after a timedelay when the water level in said chamber rises to raise said float.

7. An exhaust fan switch for mounting in the flush tank of a toilet forstarting a fan when the toilet bowl is flushed and stopping said fanafter a time delay, said switch comprising a vertically extendingcasing, means including clips for supporting said casing on the watersupply post in said tank for vertical adjustment and with a substantialportion of the length of said casing below the upper water level in saidtank, a discharge opening in the lower end of said casing, a valve fordischarging water through said discharge opening when the water level insaid tank falls below said valve and for closing said opening againstentrance of water when the water level in said tank rises above saidvalve, said casing having an opening for controlled entrance of waterfrom said tank into said casing when the water level in said tank risestoward said upper level, a float in said casing and electrical contactsactuated by said float to start said fan when the water level in saidcasing falls due to flushing of said toilet bowl and for stopping saidfan after a time delay when the water level in said chamber rises toraise said float.

No references cited.

